133 lines
4.1 KiB
Python
Executable File
133 lines
4.1 KiB
Python
Executable File
import torch
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import torch.nn as nn
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import torch.nn.functional as F
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"""
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含残差的双层 空间->时间->空间 结构模型 无效
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"""
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class DynamicGraphConstructor(nn.Module):
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def __init__(self, node_num, embed_dim):
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super().__init__()
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self.nodevec1 = nn.Parameter(
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torch.randn(node_num, embed_dim), requires_grad=True
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)
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self.nodevec2 = nn.Parameter(
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torch.randn(node_num, embed_dim), requires_grad=True
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)
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def forward(self):
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# 构造动态邻接矩阵 (N, N)
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adj = torch.matmul(self.nodevec1, self.nodevec2.T)
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adj = F.relu(adj)
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adj = F.softmax(adj, dim=-1)
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return adj
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class GraphConvBlock(nn.Module):
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def __init__(self, input_dim, output_dim):
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super().__init__()
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self.theta = nn.Linear(input_dim, output_dim)
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self.residual = input_dim == output_dim
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if not self.residual:
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self.res_proj = nn.Linear(input_dim, output_dim)
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def forward(self, x, adj):
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# x: (B, N, C)
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res = x
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x = torch.matmul(adj, x)
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x = self.theta(x)
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x = x + (res if self.residual else self.res_proj(res))
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return F.relu(x)
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class MANBA_Block(nn.Module):
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def __init__(self, input_dim, hidden_dim):
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super().__init__()
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self.attn = nn.MultiheadAttention(
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embed_dim=input_dim, num_heads=4, batch_first=True
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)
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self.ffn = nn.Sequential(
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nn.Linear(input_dim, hidden_dim),
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nn.ReLU(),
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nn.Linear(hidden_dim, input_dim),
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)
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self.norm1 = nn.LayerNorm(input_dim)
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self.norm2 = nn.LayerNorm(input_dim)
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def forward(self, x):
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# x: (B, N, C) 当 N 视为时间序列长度
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res = x
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x_attn, _ = self.attn(x, x, x)
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x = self.norm1(res + x_attn)
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res2 = x
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x_ffn = self.ffn(x)
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x = self.norm2(res2 + x_ffn)
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return x
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class SandwichBlock(nn.Module):
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"""
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空间 -> 时间 -> 空间 三明治结构
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输入/输出： (B, N, hidden_dim)
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"""
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def __init__(self, num_nodes, embed_dim, hidden_dim):
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super().__init__()
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self.graph_constructor = DynamicGraphConstructor(num_nodes, embed_dim)
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self.gc1 = GraphConvBlock(hidden_dim, hidden_dim)
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self.manba = MANBA_Block(hidden_dim, hidden_dim * 2)
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self.gc2 = GraphConvBlock(hidden_dim, hidden_dim)
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def forward(self, h):
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# 第一步：空间卷积
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adj = self.graph_constructor()
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h1 = self.gc1(h, adj)
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# 第二步：时间注意力
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h2 = self.manba(h1)
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# 第三步：空间卷积
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h3 = self.gc2(h2, adj)
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return h3
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class EXP(nn.Module):
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def __init__(self, args):
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super().__init__()
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self.horizon = args["horizon"]
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self.output_dim = args["output_dim"]
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self.seq_len = args.get("in_len", 12)
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self.hidden_dim = args.get("hidden_dim", 64)
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self.num_nodes = args["num_nodes"]
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self.embed_dim = args.get("embed_dim", 16)
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# 输入映射
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self.input_proj = nn.Linear(self.seq_len, self.hidden_dim)
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# 两层 空间-时间-空间 三明治块
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self.sandwich1 = SandwichBlock(self.num_nodes, self.embed_dim, self.hidden_dim)
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self.sandwich2 = SandwichBlock(self.num_nodes, self.embed_dim, self.hidden_dim)
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# 输出映射
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self.out_proj = nn.Linear(self.hidden_dim, self.horizon * self.output_dim)
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def forward(self, x):
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# x: (B, T, N, D)
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x_main = x[..., 0] # (B, T, N)
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B, T, N = x_main.shape
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assert T == self.seq_len
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# 投影到隐藏维 (B,N,hidden)
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x_flat = x_main.permute(0, 2, 1).reshape(B * N, T)
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h0 = self.input_proj(x_flat).view(B, N, self.hidden_dim)
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# 第一层三明治 + 残差
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h1 = self.sandwich1(h0)
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h1 = h1 + h0
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# 第二层三明治
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h2 = self.sandwich2(h1)
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# 输出
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out = self.out_proj(h2) # (B, N, H*D_out)
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out = out.view(B, N, self.horizon, self.output_dim)
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out = out.permute(0, 2, 1, 3) # (B, horizon, N, output_dim)
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return out
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